One of the major challenges in modern volcanology studies is limiting the depth of magmatic reservoirs that supply and support eruptions. However, commonly used methods such as mineral melt barometry have relatively low precision and accuracy.
In recent years, scientists have looked for ground deformation near active volcanoes using satellite imagery, earthquake data and GPS. Still, such methods can be unreliable in determining the storage depth of magma.
Scientists at Cornell University suggest that by finding microscopic, carbon dioxide-rich fluids encased in cooled volcanic crystals, they could pinpoint where magma is within a hundred meters. They’ve even found specific, microscopic clues to where magma is stored.
Esteban Gazel, a professor of engineering and lead author of the study, published in Science Advances, said: “A fundamental question is where magma is stored in the Earth’s crust and mantle. That location is important because you can estimate the risk of an eruption by pinpointing the specific location of magma rather than other signals such as a volcano’s hydrothermal system.
“Speed and precision are essential. We demonstrate the enormous potential of this improved technique in terms of speed and unprecedented accuracy. We can produce data within days of samples arriving from a site, yielding better, near-real-time results.”
During a volcanic eruption, magma flows to the Earth’s surface and erupts as lava. When deposited as part of the eruption’s fallout, fragmented fine-grained material — called tephra — can be collected and evaluated.
Because the carbon dioxide density of these inclusions is controlled by pressure, Gazel and Ph.D. student Kyle Dayton discovered how inclusions of carbon dioxide-rich fluids trapped in olivine crystals can be used to accurately identify depth.
The depth of the burning reservoir and how deep the magma was stored can be determined instantly with an instrument by measuring these fluids.
- Kyle Dayton, Esteban Gazel, Penny Wieser, Valentin R. Troll, Juan Carlos Carracedo, Hector La Madrid, Diana C. Roman, Jamison Ward, Meritxell Aulinas, Harri Geiger, Frances M. Deegan, Guillem Gisbert, Francisco J. Perez-Torrado . Deep magma storage during the 2021 La Palma eruption. Scientific progress, 2023; 9 (6) DOI: 10.1126/sciadv.ade7641